translate init-cluster script to Ruby
translate init-cluster script to Ruby

Change-Id: Ia21961935e58de0abc8effea950a999942298007
Reviewed-on: https://review.couchbase.org/c/couchbase-ruby-client/+/166063
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>

couchbase/couchbase-ruby-client,couchbase/couchbase-ruby-client,couchbase/couchbase-ruby-client